The present invention relates to a new and improved push button assembly and to a manner in which heat is transferred from the push button assembly.
Push button switch assemblies have previously utilized incandescent light sources to illuminate displays. Push button switch assemblies having such a construction are disclosed in U.S. Pat. Nos. 3,315,535 and 4,496,813. However, push button switch assemblies having incandescent light sources may require maintenance to replace failed or burnt out light sources.
It has been suggested that solid state light sources may be utilized to illuminate a display in a push button switch assembly. Known push button switch assemblies having solid state light sources to illuminate displays are disclosed in U.S. Pat. Nos. 5,659,297 and 6,153,841. When circuit components which emit heat are disposed adjacent to the solid state light sources, there is a possibility that the light sources may tend to overheat.
The present invention relates to a new and improved push button assembly which is used to move switch contacts between an actuated condition and an unactuated condition. The push button assembly includes a plurality of solid state light sources which are energizable to emit light. A display is illuminated by light from the solid state light sources when the solid state light sources are energized.
A metal heat sink is disposed adjacent to electrical circuit components which emit heat. To conduct heat away from the heat sink, the metal heat sink may be disposed in engagement with a metal housing. The heat sink may be formed by a single member or by a plurality of members. The member or members forming the heat sink may advantageously have projections which extend through side walls of a base. The projections are engagable by the metal housing to facilitate the conduction of heat between the heat sink and the housing.